1. Field of the Invention
The present invention relates to a construction for attaching, to a vehicle body, a seat belt system provided with a pretensioner mechanism in a locking portion, which mechanism is a means for tightening a seat belt in an emergency such as vehicle collision, the construction being applied to a vehicle provided with the seat belt on a seat, such as an automobile, industrial vehicle, construction machine, etc.
2. Description of Related Art
Some band-shaped safety belts (seat belts) of a seat belt system for restraining a vehicle passenger on a seat in an emergency such as vehicle collision are provided with what is called a pretensioner mechanism. The pretensioner mechanism is a mechanism for enhancing passenger restraining performance by increasing the tension of a seat belt by a cooperative action of a gas generator and a piston in a cylinder portion to instantaneously tighten the belt and hence eliminate belt looseness with respect to the passenger.
This pretensioner mechanism is configured so that the belt is instantaneously pulled toward the vehicle body side by utilizing gas pressure etc., by which the looseness of the belt is eliminated, and the belt is made to adhere closely to the passenger's body to enhance the restraining performance.
As disclosed, for example, in Patent Document 1 (Japanese Patent No. 2501075), generally, a pretensioner mechanism utilizing gas pressure includes a gas generator and a tubular cylinder that accommodates a piston moved by the pressure of generated gas, and has a construction such that a gas generator is operated by transmitting a signal of a sensor for detecting an emergency state of the vehicle, such as collision, to the gas generator via a harness and a connector, and the piston connected to the belt via a wire etc. is moved in the cylinder by the gas pressure sent from the gas generator, by which the belt is pulled in.
The above-described pretensioner mechanism is provided at a location at which mainly the belt is fixed to the vehicle body, such as a belt winding device, buckle, or lap anchor (lateral lumbar anchor) portion, of components of the seat belt system.
Also, in Patent Document 2 (Japanese Patent Provisional Publication No. 2005-81886), the configuration is such that a dummy floor is provided above a floor panel, and the cylinder portion of a pretensioner mechanism is arranged lying under the dummy floor together with a gas generator and a connector for transmitting electrical signals, by which the component members of the pretensioner mechanism are protected from an external force exerted by the passenger's foot etc. at the time of getting on and off and from water at the time of rainfall.
However, the above-described conventional techniques have the below problems.
The technique described in Patent Document 1 merely provides a pretensioner which is itself configured so that the gas generator is operated by transmitting a signal from a sensor which detects a vehicle emergency state, such as a collision, to the gas generator via the harness and the connector, and the piston connected to the belt via a wire etc. is moved in the cylinder by the gas pressure sent from the gas generator, by which the belt is pulled in. A construction for attaching the pretensioner mechanism to the vehicle body side is not disclosed.
Also, in the technique described in Patent Document 2, the configuration is such that the cylinder portion of pretensioner mechanism is arranged lying together with the gas generator and the connector for transmitting electrical signals, by which the component members of the pretensioner mechanism are protected from an external force exerted by the passenger's foot etc. at the time of getting on and off and from water at the time of rainfall. In this case, the dummy floor must be provided separately, and thus a space for installing the dummy floor is needed, so that there is a danger that the system becomes complicated and large.
Further, the pretensioner mechanism must be provided under the floor surface in the vehicle cabin. Therefore, this technique has a drawback in that the vertical range in which the pretensioner mechanism is installed is restricted.